Automatic exchange-selector.



PATENTED MAY 8, l906.

C. D.l ENOCHS.

AUTOMATIC EXCHANGE SELECTOR.

2 SHEETS-SHEET l.

yAPPLICATION FILED OCT 16 1905 fzdezar: MKZMO/q f f ff" PATENTED MAY 8, 1906. C. D. ENOCHS.

AUTOMATIC EXCHANGE SELECTOR.

APPLICATION FILED OCT. 16. 1905.

2 SHEETS-SHEET 2.

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" UNITED STATES `PATENT OEEICE.

CLAUDE D. ENOCHS, OE LA GROSSE, WISCONSIN,ASSIGrNOItA To WESTERN ELECTRIC COMPANY, OE CHICAGO, ILLINOIS. A, CORPORATION OF ILLINOIS.

AUTOMATIC v;'xox-mwst:esLise-reta..

'Speciication of Letters Patent.

Patented May 8, 1906.

pplioationlled October 16, 1905. Serial No. 282,985.

change-Selectors, ofwhich the following is a v full, clear, concise, and exact description.

My invention relates to a selector for automatic telephone-exchanges, and has for its object the simplification of .the mechanism for effecting theinterconnection of the different lines terminating at the central exchange.

My invention provides 'a selecting mechanism in `which but one magnet is used. This 4 magnet is provided with two armatures, one

carrying the stepping-pawl and fthe other controlling the retaining-pawl. .The former is arranged toy respond to each interruption of the current through themagnet, so that the stepping-pawl is actuated once for each impulsey oiD current through the magnet, while the other armature is constructed so as to respond only to` interruptions of' longer` duration andto remainattracted during the process of selection as well as when the current is constant. I am thus `enabled tov dispense with'tlie usual retaining-ma net, and thereby to simplify the selector mec anism.

I will describe my invention in detail by reference to the accompanying drawings, in whch- Figure 1 is a frontelevation of the select-or with the parts in normal position, the selector-arm carrying theterminalsof the callingline and the terminal contacts of the other lines being omitted forl the sake of clearness.

Fig'. 2 is a view similar to that of Fig. 1, showing the positionof the'parts when the selector 1s to norma 'position may be of the usual con-.

struction, and since .they form no part of my 'tension of the sprin eing actuated. Fig. 3 isa side elevation.

wherever they are invention it is deemed unnecessary to ,illustrate or describe them. l.

When a calling subscriber operates his calling mechanism in the usual manner to send a series of impulses through the magnet C, s-aid magnet attracts its armature D, which is pivoted at d to the supporting-frame, and said armature is drawn forward against the tension of the spring d/, as shown in Fig. 2. Pivoted at the upper end of the armature D is a pawl d2 in the shape of a bell-crank' lever,

' which when the armature is in its normal position is held -out of engagement with the teeth a of the ratchet-wheel by the pin d3. When the armature is drawn forward, the pawl is freed Jfrom the pin d3 and contacts with the pin d4 and is thereby forced into engagement With'the teeth a, so that each time the armature D is attracted `the wheel A is advanced one step.

E is an armature for controlling the operation of the retaining-pawl H. Said armature is mounted on one-end of a lever G, pivoted at g to theframe B. The other end of said lever is provided with aweight I. When the lever G 1s in its normal position shown in Fig. 1, a projection g thereon engages with the pawl H and holds said pawl against the h out of engagement with the. teeth a. W en the magnet U is energized, the armaturevE is attracted and engages with the split yoke F of the ma net C, asshown in Fig. 2. leased from its enga ement with the projection g and is forced -y the spring -h into engagement. with the teeth a and holds the ratchet-Wheel A in its advanced position.

While thev interrupted current is sent through the magnet C by the calling sub-l scriber in the usual manner, the steppingpawl is D actuated once for each im ulse,

thereby advancing the ratchet-wheel step by step. `The interruptions are of such frequenc however, that the armature E does not. fo low them, but remains in its attracted position. This is due to the inertia of the weight I and also to the fact that the movement of the armature E is retarded by a freezing iron-to-iron contact between said armature and the Asplit yoke F. The'pawl H therefore remainsfin en agement'with the teeth-a .and retains the w eel in its advanced position. When, however, the magnet C is The pawl H is t en re- IOO denergized for a sulhci ent perion of time,the lever G, by the force of gravity, swings back to its normal position, and in so doing the projection g kicks the retaining-pawl H Jfrom its engagement with the teeth of the ratchet- Wheel A, permitting said wheel to be returned to its normal position in the usual manner. It will be seen, therefore, that both the stepping-pawl and the retaining-pawl are actuated through the same magnet and that the usual retaining-magnet is dispensed with.

Having described my invention, I claiml. In a selector for an automatic telephoneexchange, the combination with a rotatablymounted ratchet-wheel, of a stepping-pawl and a retaining-pawlfor controlling the rotation of said Wh eel, andan electromagnet having a quick-acting armature and an armature possessing considerableinertia for controlling the operation of said pa'wls.

2. The combination jwith a rotatablymounted ratchet-wheel, ofI an electromagnet, an armature for said magnet, a pawl actuated thereby Jfor stepping said Wheel, a second armature for said magnet, means whereby said second armature is caused vto act' sluggishly when the magnet is denergized, and a retainingawl controlled by-said second armature an ada ted to engage the teeth of the ratchet-Whee when said armature is in its attracted position. v

3. The combination v with a rotatablyntounted ratchet-wheel, of an electromagnet having a divided yoke, an armature for said magnet provided with a pawl for stepping said wheel when the armature is operated, a retaining-pawl for holding said wheel in its advanced position, a second armature normally holding said retaining-pawl out of engagement with the teeth of the ratchet-wheel and adapted to engage with said divided yoke, whereby said armature is held in its attracted position While an interrupted current is sent through said magnet.

4. The combination with a rotatablymounted ratchet-Wheel, .of an electromagnet having a divided yoke, an armature for said magnet provided with a pawl for stepping said wheel when the armature is attracted, a retaining-pawl for holding said Wheel in its advanced position, a pivoted lever normally holding said retaining-pawl out of engagement with the teeth of the ratchet-wheel, a weight carried by said lever, and an armature carried by said lever adapted to engage with said divided yoke, whereby said lever is held out of engagement with said retaining-pawl while an interrupted current is sent through said magnet.

5. In a selector for an automatic telephoneexchange, the combination with a ratchet, of a stepping and a retaining pawl for controlling the movement ofsaid ratchet, an electromagnet, a quick-acting armature adapted to control the movement of the steppingpawl and a slow-acting armature adapted tov control the movement of the retaining-pawl, and a weight for, said slow-actin armature having its center of gravity but s 'ghtly displaced from a vertical line through its support.

6. In a selector for an automatic telephoneexchange, the combination with a ratchet, of a stepping and a retaining pawl for controlling the movement of said ratchet, an electromagnet, a quick-acting armature adapted to control the movement of the steppingpawl and an armature adaptedvto control they movement of said retaining-pawl, said arma-- ture having considerable inertia.

7; In a selector for an automatic telephoneexchange, the combination with a ratchet, of a stepping and a retaining pawl for controlling the movement of said ratchet, an electromagnet, a quick-acting armature adapted to control the movement of the steppingpawl and an armature adapted to control the movement of said retaining-pawl, said armature having considerable inertia but having slight retractive force.

In witness whereof I hereunto subscribe my name this 26th day of July, A. D. 1905, CLAUDE D` ENOCHS. Wvitnesses:

RUTH WARREN, OLGA JENSEN. 

